Thanks Bert. I see what your getting at. ADRESH was a word.
I just tried ADRESH as a byte and had an overflow. oops, I missed that one.
I guess I'll use the temp variable way.

There is another way I used before:
adcData[index] = (ADRESH * 256) + ADRESL
But I would put money on this way is slower than the temp variable way.